1. Field of the Invention
The present invention relates to a switch circuit, a radio-frequency module, and a communication device.
2. Description of the Related Art
Lately, there has been an increasing demand for supporting a carrier aggregation (CA) for simultaneously sending and receiving multiple signals of different frequency bands. Japanese Unexamined Patent Application Publication No. 2015-115866 discloses a circuit using a quadplexer such as that shown in FIG. 18. FIG. 18 is a schematic diagram illustrating an example of a known CA-support circuit 400.
The known CA-support circuit 400 simultaneously sends and receives multiple signals of different frequency bands by using a quadplexer (multiplexer) 420 connected to an antenna 410.
When a signal passes through a multiplexer, insertion loss occurs because of this multiplexer. For example, in the known CA-support circuit 400 shown in FIG. 18, even when a signal is sent or received in a non-CA mode, it passes through the quadplexer (multiplexer) 420, thus causing insertion loss.